Philosophy of Molecular Biology

Abstract

Ongoing empirical discoveries in molecular biology have generated novel conceptual challenges and perspectives. Philosophers
of biology have reacted to these trends when investigating the practice of molecular biology and contributed to scientific
debates on methodological and conceptual matters. Some major philosophical issues in molecular biology are as follows: First,
philosophical accounts of mechanistic explanation yield a notion of explanation in the context of molecular biology that does
not have to rely on laws of nature and comports well with molecular discovery. Second, reductionism continues to be debated
and increasingly rejected by scientists. Philosophers have likewise moved away from reduction towards integration across fields
or integrative explanations covering several levels of organisation. Third, although the gene concept has undergone substantial
transformation and even fragmentation, it still enjoys widespread use by molecular biologists, which has prompted philosophers
to understand the empirical reasons for this. At the same time, it has been argued that the notion of ‘genetic information’
is largely an empty metaphor, which generates the illusion of explanatory understanding without offering an adequate explanation
of molecular and developmental mechanisms.

Key Concepts

Mechanistic explanation yields a notion of explanation for molecular biology that does not have to invoke laws of nature.

Philosophical accounts of mechanistic explanation mesh well with how discovery in molecular biology works.

The idea that all biological knowledge can be reduced to one fundamental theory or that all explanations are reductive has
largely been abandoned.

Reductionism tends to be replaced in favour of integration across fields or explanations combining features from different
levels of organisation.

The concept of the gene has undergone substantial transformation throughout its history. Despite its more recent fragmentation,
the gene concept is still widely used.

The notion of ‘genetic information’ is largely a metaphor, generating the illusion of explanatory understanding, and cannot
be articulated in a manner conforming to mechanistic explanations of molecular and developmental processes.

Figure 1. The mechanism of protein synthesis (in eukaryotes). Transcription of DNA segments to RNA takes place in the nucleus, while the RNA's subsequent translation to protein (depicted as a chain of black dots) occurs in the cytoplasm. Image in public domain.

Figure 2. A synapse permitting signal transmission from one neuron (at the top) to another (at the bottom). The synapse includes entities such as the axon of the transmitting neuron, neurotransmitters and receptors in the wall of the receiving neuron. Image created by Thomas Splettstoesser.

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